1 /*
2 * Copyright (c) 2014 VMware, Inc. All Rights Reserved.
3 *
4 * Jesse Gross <jesse@nicira.com>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that: (1) source code
8 * distributions retain the above copyright notice and this paragraph
9 * in its entirety, and (2) distributions including binary code include
10 * the above copyright notice and this paragraph in its entirety in
11 * the documentation or other materials provided with the distribution.
12 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
13 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
14 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
15 * FOR A PARTICULAR PURPOSE.
16 */
17
18 #define NETDISSECT_REWORKED
19 #ifdef HAVE_CONFIG_H
20 #include "config.h"
21 #endif
22
23 #include <tcpdump-stdinc.h>
24
25 #include "interface.h"
26 #include "extract.h"
27 #include "ethertype.h"
28
29 /*
30 * Geneve header, draft-gross-geneve-02
31 *
32 * 0 1 2 3
33 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
34 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
35 * |Ver| Opt Len |O|C| Rsvd. | Protocol Type |
36 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
37 * | Virtual Network Identifier (VNI) | Reserved |
38 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39 * | Variable Length Options |
40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41 *
42 * Options:
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * | Option Class | Type |R|R|R| Length |
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 * | Variable Option Data |
47 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48 */
49
50 #define VER_SHIFT 6
51 #define HDR_OPTS_LEN_MASK 0x3F
52
53 #define FLAG_OAM (1 << 7)
54 #define FLAG_CRITICAL (1 << 6)
55 #define FLAG_R1 (1 << 5)
56 #define FLAG_R2 (1 << 4)
57 #define FLAG_R3 (1 << 3)
58 #define FLAG_R4 (1 << 2)
59 #define FLAG_R5 (1 << 1)
60 #define FLAG_R6 (1 << 0)
61
62 #define OPT_TYPE_CRITICAL (1 << 7)
63 #define OPT_LEN_MASK 0x1F
64
65 static const struct tok geneve_flag_values[] = {
66 { FLAG_OAM, "O" },
67 { FLAG_CRITICAL, "C" },
68 { FLAG_R1, "R1" },
69 { FLAG_R2, "R2" },
70 { FLAG_R3, "R3" },
71 { FLAG_R4, "R4" },
72 { FLAG_R5, "R5" },
73 { FLAG_R6, "R6" },
74 { 0, NULL }
75 };
76
77 static const char *
format_opt_class(uint16_t opt_class)78 format_opt_class(uint16_t opt_class)
79 {
80 if (opt_class <= 0xff)
81 return "Standard";
82 else if (opt_class == 0xffff)
83 return "Experimental";
84 else
85 return "Unknown";
86 }
87
88 static void
geneve_opts_print(netdissect_options * ndo,const u_char * bp,u_int len)89 geneve_opts_print(netdissect_options *ndo, const u_char *bp, u_int len)
90 {
91 const char *sep = "";
92
93 while (len > 0) {
94 uint16_t opt_class;
95 uint8_t opt_type;
96 uint8_t opt_len;
97
98 ND_PRINT((ndo, "%s", sep));
99 sep = ", ";
100
101 opt_class = EXTRACT_16BITS(bp);
102 opt_type = *(bp + 2);
103 opt_len = 4 + ((*(bp + 3) & OPT_LEN_MASK) * 4);
104
105 ND_PRINT((ndo, "class %s (0x%x) type 0x%x%s len %u",
106 format_opt_class(opt_class), opt_class, opt_type,
107 opt_type & OPT_TYPE_CRITICAL ? "(C)" : "", opt_len));
108
109 if (opt_len > len) {
110 ND_PRINT((ndo, " [bad length]"));
111 return;
112 }
113
114 if (ndo->ndo_vflag > 1 && opt_len > 4) {
115 uint32_t *print_data = (uint32_t *)(bp + 4);
116 int i;
117
118 ND_PRINT((ndo, " data"));
119
120 for (i = 4; i < opt_len; i += 4) {
121 ND_PRINT((ndo, " %08x", EXTRACT_32BITS(print_data)));
122 print_data++;
123 }
124 }
125
126 bp += opt_len;
127 len -= opt_len;
128 }
129 }
130
131 void
geneve_print(netdissect_options * ndo,const u_char * bp,u_int len)132 geneve_print(netdissect_options *ndo, const u_char *bp, u_int len)
133 {
134 uint8_t ver_opt;
135 uint version;
136 uint8_t flags;
137 uint16_t prot;
138 uint32_t vni;
139 uint8_t reserved;
140 u_int opts_len;
141
142 ND_PRINT((ndo, "Geneve"));
143
144 ND_TCHECK2(*bp, 8);
145
146 ver_opt = *bp;
147 bp += 1;
148 len -= 1;
149
150 version = ver_opt >> VER_SHIFT;
151 if (version != 0) {
152 ND_PRINT((ndo, " ERROR: unknown-version %u", version));
153 return;
154 }
155
156 flags = *bp;
157 bp += 1;
158 len -= 1;
159
160 prot = EXTRACT_16BITS(bp);
161 bp += 2;
162 len -= 2;
163
164 vni = EXTRACT_24BITS(bp);
165 bp += 3;
166 len -= 3;
167
168 reserved = *bp;
169 bp += 1;
170 len -= 1;
171
172 ND_PRINT((ndo, ", Flags [%s]",
173 bittok2str_nosep(geneve_flag_values, "none", flags)));
174 ND_PRINT((ndo, ", vni 0x%x", vni));
175
176 if (reserved)
177 ND_PRINT((ndo, ", rsvd 0x%x", reserved));
178
179 if (ndo->ndo_eflag)
180 ND_PRINT((ndo, ", proto %s (0x%04x)",
181 tok2str(ethertype_values, "unknown", prot), prot));
182
183 opts_len = (ver_opt & HDR_OPTS_LEN_MASK) * 4;
184
185 if (len < opts_len) {
186 ND_PRINT((ndo, " truncated-geneve - %u bytes missing",
187 len - opts_len));
188 return;
189 }
190
191 ND_TCHECK2(*bp, opts_len);
192
193 if (opts_len > 0) {
194 ND_PRINT((ndo, ", options ["));
195
196 if (ndo->ndo_vflag)
197 geneve_opts_print(ndo, bp, opts_len);
198 else
199 ND_PRINT((ndo, "%u bytes", opts_len));
200
201 ND_PRINT((ndo, "]"));
202 }
203
204 bp += opts_len;
205 len -= opts_len;
206
207 if (ndo->ndo_vflag < 1)
208 ND_PRINT((ndo, ": "));
209 else
210 ND_PRINT((ndo, "\n\t"));
211
212 if (ethertype_print(ndo, prot, bp, len, len) == 0) {
213 if (prot == ETHERTYPE_TEB)
214 ether_print(ndo, bp, len, len, NULL, NULL);
215 else
216 ND_PRINT((ndo, "geneve-proto-0x%x", prot));
217 }
218
219 return;
220
221 trunc:
222 ND_PRINT((ndo, " [|geneve]"));
223 }
224